Armrest arrangements in convertible aircraft passenger seating

ABSTRACT

An aircraft passenger seating unit providing seats for two or more passengers abreast which is convertible to provide different widths of seats by moving seat parts laterally with respect to one another between two configurations, wherein the seats are defined by an end armrest (4, 5) at each side of the unit and by a pair of intermediate armrests (6, 7, 8, 9) between the or each pair of adjacent seats and lost-motion devices move the intermediate armrests apart when the unit is moved to the configuration providing wider seats and enable them to be moved together when the unit is moved to the configuration providing narrower seats. The lost-motion devices may be headed rods.

TECHNICAL FIELD

Aircraft passenger seating is commonly constructed in units eachcomprising seats for two or more passengers abreast, mounted on asupport frame having leg structure terminated by feet designed to engagereleasably with a pair of parallel tracks secured in the aircraft cabinfloor and extending longitudinally thereof.

BACKGROUND ART

Because some passengers are willing to pay more than others for travelon the same journeys, aircraft operators have developed fare structureswhich provide different fares for passengers occupying seats whichprovide different degree of comfort. In particular the seats havedifferent widths and usually different lateral pitches. Because theproportion of passengers who wish to travel on the different fares onany one flight cannot usually be predicted long in advance there havebeen developed over a number of years convertible seating units whichwhich can be manipulated to vary the width and frequently also thenumber of the seats provided in a unit. For example, in U.S. Pat. No.4,533,175 a unit is described which provides either three narrow seatsabreast, separated by two armrests or two wider seats abreast, separatedby a single wider armrest formed from a part of the backrest whichpreviously served the middle seat, the said two armrests being foldeddown to an inoperative position to make way for the wider armrest. In aunit described in European Patent Specification No. 0 385 861 B1 whichlikewise provides either three narrow seats or two wider seats there aretwo intermediate armrests between the two outer seats, mounted onpantograph-type linkages enabling them to be moved laterally betweenfirst positions in which they will support a loose table between twowider seats and second positions spaced more widely apart in which theydefine a third seat between two narrower seats.

More recently there have been developed convertible seating unitsproviding two or more seats abreast in which certain seats or parts ofseats are laterally movable with respect to others so that the lateralpitch or spacing between them and/or their widths can be changed.Usually there is some locking means for fixing the laterally movableseats or parts releasably in different positions. Typically there aretwo such positions, one providing narrow seats, usually with narrowlateral spacing between them, for example for "Tourist Class"passengers, and one with wider seats, usually with wider lateralspacing, for example for "Business Class" passengers. Examples of suchunits are described and illustrated in U.S. Pat. Nos. 3,893,729,4,881,702, 5,104,065, 5,131,607 and 5,178,345 and in European PatentApplication No. 0 530 900 A1.

In British Patent Specification No. 2 249 721 A (WO 90/11930) aconvertible seating unit is described which provides either narrow seatsabreast, separated by two armrests (called "arm dividers") in a firstfixed position or two wider seats abreast, separated by the same twoarmrests which have been moved closer together to a second fixedposition and by a backrest part of the middle seat of the three, whichhas been folded down to co-operate with the armrests to form a tray foruse by occupants of the two seats. In one embodiment each outer seat hasa seat back comprising a central frame and interengagable shell sectionswhich are laterally slidable and co-operate with alternative removablepieces of foam padding of two different widths which are usedselectively to provide either narrow seat backs for the three-seatconfiguration or wider seat backs for the two-seat configuration. Inanother embodiment the side seat backs are laterally movable on theframe of the unit.

In U.S. Pat. No. 5,131,607 a seating unit providing three seats abreastis described which is convertible between configurations providing threenarrower seats and three wider seats. The three seats are constructed onthree separate frame parts, the first and second of which are laterallymovable relative to each other and to the third to enable the unit to beconverted between the two configurations. The third frame part is fixedto the remainder of the frame and intended to be positioned adjacent tothe sidewall or window of an aircraft cabin. The first and second frameparts and the second and third frame parts respectively are connectedtogether by what will be termed "lost-motion devices" which permit adegree of relative movement between two components followed by movementof both components together or, in the case in which one component isfixed, by the fixing of both components. In the embodiment illustratedin the drawings accompanying U.S. Pat. No. 5,131,607 the lost-motiondevices connecting the frame parts together are rods. A first rod issecured by one end to the third frame part, passes through a bore on thesecond frame part and extends a distance beyond the end of the boreequal to the desired travel of the second frame part relative to thethird. At its free end it carries a stop member which will not passthrough the bore, for example a nut, a circlip or an enlarged head. Asecond rod secured by one end to the first frame part, which will beadjacent to an aisle when the unit is in position on an aircraft,similarly connects it to the second frame part. The unit is convertedfrom the narrower configuration to the wider configuration simply byreleasing a lock mechanism and pulling the first frame part towards theaisle. The first frame initially moves away from the second frame partuntil the stop member contacts a wall of the second frame partsurrounding the bore through which the rod passes. On further moving thefirst frame part the stop member moves the second frame part with it,away from the third frame part. The second frame part slides along thefirst rod until the stop member contacts a wall of the second frame partaround the bore through which the rod passes. That contact halts themovement of the second frame part and defines the wider configuration ofthe unit. The length of the rods determine the relative positions of theframe parts in that configuration and there is a locking device to lockthem releasably in those positions.

Conversion back to the narrower configuration is simply a matter ofpushing the first frame part inwardly towards the second and third afterreleasing the locking device. The first frame part will approach thesecond, the second rod sliding through the bore in the second frame partuntil the two frame parts make contact, whereupon further inwardmovement of the first frame part will push the second frame partinwardly towards the third. The first rod will slide through the bore inthe second frame part until the second and third frame parts makecontact. The narrower configuration has then been regained.

End armrests are secured to the first and third frame parts andintermediate armrests are mounted between the first and second frameparts and the second and third frame parts. The end armrest secured tothe first frame part moves laterally with it during conversion of theunit between the two configurations. The intermediate armrests aremounted on upward extensions of the rear ends of the side members of thesecond frame part and they are engaged respectively by lost-motiondevices mounted on the first and third frame parts. These lost-motiondevices comprise rods extending laterally from the said respective frameparts which pass through bores in the intermediate armrest mountings andsome distance beyond the ends of the bores and are terminated by stopmembers such as nuts which will not pass through the bores. Duringconversion of the unit from the narrower configuration to the wider, asthe first seat frame part moves laterally away from the second, the rodslides in the bore in the mounting of the intermediate armrest betweenthe first and second frame parts until its stop member abuts against thewall surrounding the bore. Thereafter the intermediate armrest moveswith the first frame part, away from the second frame part until thelatter begins to move as described above. That beginning movement slidesthe bore in the second intermediate armrest mounting along the rod whichis secured to the third frame part until its stop member in turn abutsagainst the wall surrounding the bore. Then the second intermediatearmrest is moved laterally away from the third frame part until thelateral movements are completed as described above.

The lengths of the rods which move the intermediate armrests areadjusted so that when conversion to the wider configuration is completethe intermediate armrests are located so that the widths of the threeseats defined between the end and intermediate armrests are adjustedmore or less equally. However, as the end armrests are fixed in relationto the first and third frame parts, the two side seats are each adjustedonly on one side whereas the middle seat is adjusted at both sides.Therefore whilst the backrest of the middle seat is located centrallybetween the intermediate armrests in both the narrower and widerconfigurations and the seat always appears symmetrical, the backrest ofa side seat, if located centrally between the end and intermediatearmrests which define the seat in one configuration, will be off-centrein the other configuration, giving a non-symmetrical appearance andmaybe less than maximum comfort to a passenger occupying the seat.Furthermore, because the object of the narrower configuration is toaccommodate more passengers in the available space, the intermediatearmrests in convertible seating units are usually made as narrow as ispossible compatible with providing adequate separation of adjacent seatsand a moderate degree of comfort in the narrower configuration of theunit. On the other hand the wider configuration is intended to providegreater comfort for fewer passengers paying a higher fare, so the narrowintermediate armrests are not then entirely appropriate. Furthermore,whilst sharing a single armrest might be acceptable to passengers payinga lower fare scale, it is likely to be unacceptable to passengers payinga higher fare for wider seats or wider spaced seats.

In all the prior proposals for convertible seating which have beendescribed and in all others known to the Applicants there is only onearmrest between adjacent seats is at least one configuration of theunit.

DISCLOSURE OF THE INVENTION

According to this invention an aircraft passenger seating unit providingseats for two or more passengers abreast which is convertible to providedifferent widths of seats by moving seat parts laterally with respect toone another between two configurations, in which the seats are definedby an end armrest at each end of the unit and intermediate armrestsbetween the or each pair of adjacent seats, is characterized in thatthere is a pair of intermediate armrests between the or each pair ofadjacent seats and in that the end armrests and one of the or each pairof intermediate armrests are each connected to the adjacent seat part bya lost-motion device, the said lost-motion devices permitting, when theseating unit is being converted between the two configurations, limitedrelative lateral movement between each of the said armrests and the saidadjacent seat part and the intermediate armrests of the or each saidpair are connected to each other by another lost-motion devicepermitting limited relative lateral movement between them.

With this arrangement, when the seating unit is converted between itstwo configurations all the seat parts and all the armrests except oneend armrest, which may be fixed in an aircraft, are moved laterally withrespect to that one end armrest. Thus in each configuration each seatbackrest can be more or less centrally located between the armrestsdefining the seat and in the wider configuration the two intermediatearmrests between adjacent seats may be spaced apart so that sharing orarmrests is clearly unnecessary. Conversely, the intermediate armrestsmay be close together in the narrow configuration so that they occupy aminimal part of the width of the unit. Indeed, they are preferably incontact with each other in that configuration.

Each lost-motion device preferably comprises a rod or like elongatedmember secured to a part of one of two components between which lostmotion is provided, passing freely through a bore in an adjacent part ofthe other component of the two and having on the side of the adjacentpart remote from the part to which it is secured a head or attached nutor other enlargement which will not pass through the bore, the head, nutor enlargement being spaced from the said side of the adjacent part adistance equal to the desired lost motion. However, other types oflost-motion device such as a flexible connecting member between theparts or an elongated ring-like link surrounding the parts may equallybe used. Its essential function is to permit one of two parts which arein contact to move away from the other a pre-determined distance andthen to connect the parts together so that further movement of the saidone part will also move the other part. Likewise, when the parts arespaced apart the said pre-determined distance it is to permit the saidone part to be moved towards the other until contact between them isre-established, after which further movement of the said one part in thesame direction will also move the other or, if one of the other part isfixed no further movement of the said one part will be possible.

Further according to this invention, an aircraft passenger seating unitproviding seats for two passengers abreast separated by intermediatearmrests which is convertible to provide different widths of seats bymoving a part of one seat laterally with respect to a part of the otherseat between two positions is characterized in that there are twointermediate armrests between the seats which are capable of relativelateral movement between a closely spaced relationship and a more widelyspaced relationship and in that automatic means are included for movingthe intermediate armrests to their more widely spaced relationship whenthe said part of one seat is moved to its position providing wider seatsand for permitting them to move to their closely spaced relationshipwhen the said part is moved to its position providing narrower seats.

Still further according to the invention, an aircraft passenger seatingunit providing seats for more than two passengers abreast separated byintermediate armrests which is convertible to provide different widthsof seats by moving a part of one end seat laterally with respect to apart of the other end seat between two positions is characterized by apair of intermediate armrests separating each two adjacent seats, theintermediate armrests of each said pair being capable of relativelateral movement between a closely spaced relationship and a more widelyspaced relationship, and by automatic means for moving the intermediatearmrests to their more widely spaced relationship when the said part ofone end seat is moved relative to the said part of the other end seat toits position providing wider seats and for permitting them to move totheir more closely spaced relationship when the said part is moved toits position providing narrower seats.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is illustrated by way of example by theaccompanying drawings in which:

FIG. 1 is a diagrammatic cross-sectional view of part of a passengeraircraft cabin, looking towards the rear, showing a seating unit whichprovides three seats abreast, the unit being in the configurationproviding narrower seats,

FIG. 2 is a similar view showing the seating unit converted to providethree wider seats abreast,

FIG. 3 is a plan of the seat cushion support frame of the seating unitshown in FIGS. 1 and 2 in the configuration providing three narrowerseats,

FIG. 4 is a view similar to FIG. 3 showing the unit in the configurationproviding three wider seats,

FIG. 5 shows a detail of FIG. 3 to a larger scale,

FIG. 6 is a section on the line B--B of FIG. 3, drawn to a larger scale,and

FIG. 7 is a section on the line C--C of FIG. 4, drawn to a larger scale.

BEST MODE OF CARRYING OUT THE INVENTION

FIGS. 1 and 2 show a little more than half the width of the aircraftcabin, the centre-line CL of which is shown in chain-dotted lines. Theright hand seating unit shown provides seats 1, 2, 3 for threepassengers abreast with end armrests 4, 5 and two intermediate armrestsbetween adjacent seats. Intermediate armrests 6 and 7 are between seats1 and 2 and intermediate armrests 8 and 9 are between seats 2 and 3. Theseating unit is constructed on a support frame which is illustrated inFIGS. 3 and 4 and will be described in detail with reference to thosefigures. The seat frame is secured in conventional manner to anchoringtracks 10 and 11 which extend longitudinally along the floor 12 of theaircraft. The seat frame is extendible towards the centre-line of theaircraft so that the three seats may be made wider. Apart from the pairsof intermediate armrests 6, 7 and 8, 9 this is is similar to what hasbeen disclosed in the above-mentioned U.S. Pat. No. 5,131,607 and asdescribed in that Specification there may be in the left hand side ofthe cabin a seating unit which can either be extended laterally toprovide three seats abreast of width similar to those shown in FIG. 1 orbe retracted to provide two wider seats of width similar to those shownin FIG. 2. Thus the two seating units can either provide six narrowerseats abreast, say for "Tourist" class passengers, with a narrow aislebetween them which is more or less central in the cabin or five widerseats, say for "Business" class passengers, with a wider aisle betweenthem which is offset to the left of the cabin. Such arrangements areknown and described inter alia in the said U.S. Specification so theleft hand seating unit will not be described further.

End armrest 4 is on the aisle end of the unit and end armrest 5 isadjacent to the wall 13 of the aircraft cabin and is fixed to it by abracket 14. In the narrower configuration shown in FIG. 1, the seatcushions 1c, 2c and 3c and the seat backrests 1b, 2b and 3b are closetogether and the intermediate armrests of each pair are in contact so asto occupy as little of the width of the unit as possible. Typically thewidth between the armrests defining each seat is of the order of 161/2to 17 inches (approximately 420 to 430 mm.). In the wider configuration,shown in FIG. 2, the seat cushions and backrests and the intermediatearmrests of each pair are spaced apart and the width between thearmrests defining each seat is increased to 19 or 20 inches(approximately 480 mm.). The conversion is all performed by a singleaction of pulling on the handle 15 on the aisle end armrests 4 afterreleasing locking means (not shown) which holds the parts in eitherconfiguration. Releasing may be performed by the same action, asdescribed in U.S. Pat. No. 5,131,607. Conversion back to the narrowerconfiguration is a simple matter of pushing on the handle or the aisleend armrest 4 after releasing the locking means.

The seat cushion support frame shown in FIG. 3 comprises three frameparts 16, 17 and 18 for supporting the three seats 1, 2, 3. The aisleend frame part 16 comprises two side sections 19, 20 joined by two tierods 21, 22. Middle frame part 17 comprises two side sections 23, 24joined by two tie rods 25, 26 and the wall end frame part 18 comprisestwo side sections 27, 28 joined by two tie rods 29, 30. The sidesections of the frame parts 16 and 7 and the inner side section 20 ofthe aisle side frame part 16 are all slidably mounted on a pair ofparallel tubes 31, 32 which are carried by the frame shown in FIGS. 1and 2 which is secured to the aircraft floor 12 by the tracks 10 and 11.The aisle side end armrest 4 is secured to two tubes 33, 34 which are asliding fit in the tubes 31, 32 so that the armrest may be movedlaterally towards the aisle. The aisle side section 19 of the aisle sideframe part 16 is slidable on the tubes 33, 34 so that the frame part 16may be moved laterally towards the aisle with respect to the tubes 31,32.

Aisle end armrest 4 is connected to the aisle side section 19 of aisleside frame part 16 by a lost-motion device comprising a pair of headedrods 35 passing slidably through bores in the section 19 and secured tothe armrest. When the armrest 4 is moved towards the aisle, the rods 35first slide through the section 19 until their heads 36 abut against theside of the section, when further movement carries the section 19 andthus the whole of the frame part 16 towards the aisle. The length of therods 35 determines the extent of the lost-motion of the armrest 4 beforemovement of the frame part 16 commences and may be adjustable, forexample by screwing the rods into the armrest.

Aisle side frame part 16 is similarly connected to the middle frame part17 by a lost-motion device comprising headed rods 37 secured to section20 and passing through bores in side sections 23, middle frame part 17is connected to the wall side frame part 18 by a lost-motion devicecomprising headed rods 38 secured to section 27 and passing throughbores in section 24 and the wall side frame part 18 is connected to thewall side end armrest 5 by headed rods 39 secured to the armrest andpassing through bores in the section 28. Thus by pulling on the aisleside end armrest 4 the three frame parts are all moved towards the aislein a growing chain-like action. The action is reversed if the aisle sideend armrest 4 is then pushed towards the wall 13, of the aircraft, therods successively sliding through the bores until spacers on the rodsmake contact with walls surrounding the ends of the bores. This is shownto a larger scale in FIG. 5, which shows detail of a rod 37 having ahead 40 which passes through a bore 41 in the section 23 of the middleframe part 17 and is screwed into the section 20 of the aisle side framepart 16. A spacer 42 on the rod determines the minimum spacing betweenthe sections 20 and 21, in the narrower configuration of the seatingunit, and the legth of the rod determines the maximum spacing betweenthem, in the wider configuration of the unit. This is all quite similarto what is described in U.S. Pat. No. 5,131,607 excepting for themovement of the end armrest 4 relative to the frame part 16 and themovement of the frame part 18 relative to the end armrest 5.

Parts of the intermediate armrests 6, 7, 8 and 9 are included in FIGS. 3and 4 to show their location in relation to the frame parts 16 to 18.The armrests 6 and 9 are mounted on upward extensions of the rear endsof the sections 20 and 27 of the frame parts 16 and 18 and the armrests7 and 8 are mounted on support members which are mounted between theadjacent sections 20 and 23 and 24 and 27. Details are shown to a largerscale in FIGS. 6 and 7 which show the mounting of the armrests 8 and 9.The mounting of the armrests 6 and 7 is exactly the same but inmirror-image.

Intermediate armrest 9 is pivotally mounted on the section 27 of framepart 18 by a pin 43 and moves laterally with the frame part. Theadjacent section 24 of the middle frame part 17 is connected to thesection 27 by a pair of guide rods 44 which are secured in bores in thesection 24 by grub screws 45 and are received slidably in bushes 46mounted in bores in the section 27. Thus when the section 24 moveslaterally away from the section 27 as previously described the rods 44slide in the bushes 46. An armrest support member 47 is slidably mountedon the rods 44 and the armrest 8 is pivotally mounted on the supportmember by a pin 48. The support member 47 is partially hollow and isconnected to the section 24 by a lost-motion device comprising a rod 49passing through bores in the section 24 and one wall 50 of the hollowpart 51 of the support member. It is connected to the section 27 by alost-motion device comprising a rod 52 passing through bores in thesection 24 and the other wall 53 of the hollow part 51. The rods 49 and52 have heads 54, 55 which are accommodated in recesses 56, 57 in thesections 24 and 27 respectively and circlips 58 which are larger thanthe bores in the walls of the hollow part 51 are fitted to the ends ofthe rods within the hollow part to prevent them being withdrawn from it.A spacer 59 is clamped to the section 27 by studs and nuts 60 to limitthe movement of the support member 47 towards the section 27.

FIG. 6 shows the intermediate armrests 8 and 9 and associated parts intheir relationship in the narrower configuration of the seating unit andFIG. 7 shows them in their relationship in the wider configuration. Fromthe position shown in FIG. 6, as the middle frame part 16 moveslaterally away from the frame part 17, the section 24 moves away fromthe section 27, the rods 44 sliding in the bushes 46 as described above.At the same time, the rod 49 slides in the bores in the section 24 andthe wall 50 of the hollow part 51 of the support member 47, permittingthe section 24 to move away from the support member until the head 54 ofthe rod abuts the base of the recess 56 and the circlip 58 abuts thewall 50. On further movement of the section 24 away from the section 27,the support member 47 and the intermediate armrest 8 are moved bodilywith the section 24 and the rod 52 is drawn through the bore in thesection 27 until the head 55 abuts against the base of the recess 57,which must coincide with the abutment of the heads of the rods 38 withthe side of the section 24. The parts are then in the relationship shownin FIG. 7, corresponding to the wider configuration of the seating unit,with the armrest 8 spaced laterally from both the armrest 9 and thesection 24.

In converting the unit back to its narrower configuration, by pushing onthe handle 15 and/or the aisle end armrest towards the inboard end ofthe unit, the rods of the various lost motion devices slide back intheir respective bores, starting with the rods 35 and continuing insequence from aisle end to inboard end. In each case the rod slidesuntil the parts connected by it make contact and the part one the aisleside then pushes the other towards the inboard end. In the case of theintermediate armrests 8 and 9, from the positions shown in FIG. 7 theside section 24 is moved towards the support member 47 after the sidemember supporting aisle side armrest 4 has contacted the side section 19and the spacers 42 on the rods 37 have contacted the side section 23.The rod 49 slides in the bores in the side member 24 and the supportmember 47 until those two components make contact as shown in FIG. 6,then the support member 47 and the armrest 8 are moved towards theinboard end of the unit. The rod 52 slides in the bores in the sidesection 27 and the spacer 59 until the support member 47 contacts thespacer and the side section 24 of the middle frame part 17 contacts thespacers 42 on the rods 38. The two intermediate armrests 8 and 9 arethen close together as in FIG. 6. Further movement of the handle 15and/or aisle end armrest towards the inboard end of the unit causes theinboard frame part 18 to move towards the inboard armrest, sliding overthe rods 39 until the movement is completed when the side section 28contacts the spacers on the rods 39. The unit is then in the narrowerconfiguration shown in FIGS. 3 and 6.

Whilst the embodiment described and illustrated by the drawings is aunit providing seats for three passengers, the invention is equallyapplicable to units providing two seats and to units providing more thanthree seats. Referring to FIGS. 3 and 4, it may be seen that a two-seatunit could be constructed by shortening the tubes 31, 32, discarding theside sections 20 and 23 and associated armrest components and tie rods25 and 26 and connecting the tie rods 21 and 22 directly to side section24. Likewise, a unit providing more than three seats could beconstructed by increasing the length of the tubes 31, 32 and adding oneor more complex middle frame parts 17 between the side sections 20 and23.

INDUSTRIAL APPLICATION

Setting units embodying the invention are useful in anypassenger-carrying aircraft which is designed to carry more than a smallnumber, say five or six, of passengers. The invention providesconvertible seating units which provide improved comfort for passengersthan previously-known units. The invention includes the fitting of suchseating units in an aircraft and an aircraft having such seating unitsfitted.

I claim:
 1. An aircraft passenger seating unit providing seats (1, 2, 3) for two or more passengers abreast which is convertible to provide different widths of seats by moving seat parts laterally with respect to one another between two configurations, in which the seats are defined by an end armrest (4, 5) at each end of the unit and intermediate armrests (6, 7, 8, 9) between the or each pair of adjacent seats, characterized in that there is a pair of intermediate armrests (6-7, 8-9) between the or each pair (1-2, 2-3) of adjacent seats and in that the end armrests (4, 5 and one of the or each pair of intermediate armrests (6-7, 8-9) are each connected to the adjacent seat part (19, 23, 24, 28) by a lost-motion device (35, 49, 39), the said lost-motion devices permitting, when the seating unit is being converted between the two configurations, limited relative lateral movement between each of the said armrests and the said adjacent seat part and the intermediate armrests of the or each said pair are connected to each other by another lost-motion device (52) permitting limited relative lateral movement between them.
 2. An aircraft passenger seating unit as claimed in claim 1 providing three seats abreast characterized in that the said one of each pair of intermediate armrests (7, 8) is connected by a lost-motion device (49) to a part (24) of the middle seat.
 3. An aircraft passenger seating unit as claimed in claim 1 wherein each lost-motion device comprises an elongated member secured to one of the two components connected by it, passing freely through a bore in the other component connected by it and having on a side of the other component remote from the component to which it is secured a head while will not pass through the bore, the head or enlargement being spaced from the said side a distance equal to the desired lost motion.
 4. An aircraft having fitted therein an aircraft passenger seating unit as claimed in claim
 1. 5. An aircraft passenger seating unit providing seats for two passengers abreast separated by intermediate armrests which is convertible to provide different widths of seats by moving a part of one seat laterally with respect to a part of another seat between two positions is characterized in that there are two intermediate armrests (8, 9) between the said seats (1, 3) which are capable of relative lateral movement between a closely spaced relationship and a more widely spaced relationship and in that automatic means are included for moving the intermediate armrests to their more widely spaced relationship when the said part of one seat is moved to its position providing wider seats and for permitting them to move to their closely spaced relationship when the said part is moved to its position providing narrower seats.
 6. An aircraft seating unit as claimed in claimed in claim 5, wherein the automatic means comprises lost-motion devices (49,52) connecting one of the or each pair of intermediate armrests respectively to a part of an adjacent seat and to the other intermediate armrest of the pair.
 7. An aircraft passenger seating unit as claimed in claim 6 wherein each lost-motion device comprises an elongated member secured to one of the two components connected by it, passing freely through a bore in the other component connected by it and having on a side of the other component remote from the component to which it is secured a head which will not pass through the bore, the head or enlargement being spaced from the said side a distance equal to the desired lost motion.
 8. An aircraft passenger seating unit providing seats for more than two passengers abreast separated by intermediate armrests which is convertible to provide different widths of seats by moving a part (15) of one end seat (1) laterally with respect to a part (5) of the other end seat (3) between two positions is characterized by a pair of intermediate armrests (6-7, 8-9) separating each two adjacent seats, the intermediate armrests of each said pair being capable of relative lateral movement between a closely spaced relationship and a more widely spaced relationship, and by automatic means for moving the intermediate armrests to their more widely spaced relationship when the said part of one end seat is moved relative to the said part of the other end seat to its position providing wider seats and for permitting them to move to their more closely spaced relationship when the said part is moved to its position providing narrower seats.
 9. An aircraft passenger seating unit as claimed in claim 8 wherein the automatic means comprises lost-motion devices (49, 52) connecting one of the or each pair of intermediate armrests respectively to a part of an adjacent seat and to the other intermediate armrest of the pair.
 10. An aircraft passenger seating unit as claimed in claim 9 wherein each lost-motion device comprises an elongated member secured to one of the two components connected by it, passing freely through a bore in the other component connected by it and having on a side of the other component remote from the component to which it is secured a head which will not pass through the bore, the head or enlargement being spaced from the said side a distance equal to the desired lost motion. 